| maxpath(str, r, st) = 2 + # refs, st[r -- fs '] = refval(r0), # refs + 1 < maxpath(str, r0, st), is_obj(str, r, st), fs ' ∈ instfields(st[r -- _type] .type .class), validrefs(str, r ' + refs + r1 ', st[r -- _type] .type, st), maxpath(str, r, st) ≤ maxpath(str, r0, st) ⊦ # validrefset(str, r0, st) = 0, validrefset(str, r0, st) = ∅, r = r1, # validrefset(str, r, st) = 0, validrefset(str, r, st) = ∅, dups(refs), r1 ∈ refs, r ∈ refs, has_reffield(r1, st), cyclic(str, r, st), junkref(str, r, st) |
⊦ validrefset(str, r, st) ≠ ∅ → (∃ refs. refs ∈ validrefset(str, r, st) ∧ maxpath(str, r, st) = # refs)
validrefset(str, r0, st) ≠ ∅ → (∃ refs. refs ∈ validrefset(str, r0, st) ∧ maxpath(str, r0, st) = # refs), maxpath(str, r, st) = 2 + # refs, st[r -- fs '] = refval(r0), # refs + 1 < maxpath(str, r0, st), is_obj(str, r, st), fs ' ∈ instfields(st[r -- _type] .type .class), validrefs(str, r ' + refs + r1 ', st[r -- _type] .type, st), maxpath(str, r, st) ≤ maxpath(str, r0, st) ⊦ # validrefset(str, r0, st) = 0, validrefset(str, r0, st) = ∅, r = r1, # validrefset(str, r, st) = 0, validrefset(str, r, st) = ∅, dups(refs), r1 ∈ refs, r ∈ refs, has_reffield(r1, st), cyclic(str, r, st), junkref(str, r, st)
[[CONCRETESIMPRULES : ()], [EXTRATERMS : (str, r0, st)]]